The invention concerns an apparatus for servicing vehicle wheels including a wheel balancing device and a tire changing device.
Such an apparatus is known from U.S. Pat. No. 5,385,045. The known apparatus has a spindle shaft which is used to assemble and disassemble a tire by means of tire changer tools and to measure forces created by an unbalance of the vehicle wheel. The unbalance measuring means include force transducers which are operatively connected to the spindle shaft. The vehicle wheel is driven by hand or by an additional motor, for instance by a frictional motor. During the assembling of the tire to the wheel rim and the disassembling of the tire from the wheel rim, strong forces are applied to the tire and the wheel rim which are mounted on the spindle shaft. The transducers which measure the forces created by an unbalance of the vehicle wheel are operatively connected to the spindle shaft and therefore the forces applied during the assembling and disassembling of the tire can act onto the force transducers via the spindle shaft and influence the transducer sensitivity.